1. Field of the Invention
This invention relates to therapeutic and prophylactic devices, and more particularly to a method for generating compressive pressures in a multi-chambered sleeve which is applicable to a patient's limb.
2. Prior Art
Velocity of the flow of blood in patient's arms and legs, particularly the legs, markedly decreases during the confinement of the patient. This slow-down in the velocity of blood in those extremities causes a pooling of stasis of blood which is particularly pronounced during surgery, immediately after surgery, and when the patient has been confined to bed for extended periods of time. The stasis of blood is a significant cause of the formation of thrombi in the patient's extremities, which would have a severe deleterious effect on the patient. Additionally, in certain patients, it is desirable to move fluid out of interstitial spaces in the tissues of their extremities, in order to reduce swelling associated with edema in those extremities, or for the treatment of ulcers caused by insufficient venous return.
U.S. Pat. No. 4,013,069 to Hasty, discloses a sequential intermittent compression device for applying compressive pressures against a patient's limb, from a source of pressurized fluid.
U.S. Pat. No. 4,338,923 shows an inflatable-cell body treating apparatus having a compressor attached to a receiver which directs the compressed air through a reduction valve then to an inlet port of a rotary distributor, eventually to an inflatable band.
U.S. Pat. No. 3,862,629 shows a fluid pressure control apparatus including a complicated oscillatory valve arranged from a supply system to an exhaust, which feeds a plurality of inflatable chambers disposed about a patient's limb.
U.S. Pat. No. 2,528,843 discloses an intermittent pressure generator comprising a piston-cylinder arrangement with a plurality of take-off tubes in communication with the cylinder, to supply pressurized fluid to a sleeve.
Some of the prior art compressive devices are expensive to manufacture, are complicated and cumbersome, and inconvenient to use, particularly in a home care environment, where sophisticated technical help is not readily available.
It is an object of the present invention to provide a method for sequentially generating fluid pressures and providing such compressive fluid to a sleeve adapted about a patient's limb.
It is a further object of the present invention to define a method for operating a small, self-contained compressive device that is easy to use and carry, with minimum inconvenience.